Chicken pox - you only get it once. If it reappears, it's either as shingles, or what you had the first time wasn't chicken pox (lots of viruses give you a rash). In a child, chicken pox is mild, but much more serious in adults, and potentially fatal to pregnant women and unborn children. In the UK, 90% of adults have natural immunity, and as it's mild the vaccination isn't routine.
Mumps - mild in children, serious in adults.
Measles - avoid at all costs. Get vaccinated. The disease can be devastating, even fatal, and can also cause long term problems in the form of encephalitis (brain infection) that appears 10 years later.
Sorry about your finger Bouncy
What's up with this glass? Excuse me? Excuse me? This is my glass? I don't think so. My glass was full! And it was a bigger glass!